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Silvia Franzoni

@kfornaz.bsky.social

Cosmologist, particle physicist, teacher, classical dancer (RAD and Vaganova), yoga, cats and dogs. Mom of leukemia free son

34 Followers  |  107 Following  |  3 Posts  |  Joined: 04.02.2024  |  1.7284

Latest posts by kfornaz.bsky.social on Bluesky

I find happiness in the smallest of moments. Thanks, library for these moments

25.02.2025 19:01 — 👍 0    🔁 0    💬 0    📌 0

I discover the marks of others, their thoughts etched in the margins, like secret whispers from a distant world. It’s like writing with a 4B pencil, its softness gliding over the paper, sketching equations and leaving behind a gentle, pleasing hum.

25.02.2025 19:00 — 👍 0    🔁 0    💬 1    📌 0

Among the things that bring me joy, one is the fragrance of books, the delicate scent that lingers in the air. I trace my fingers along the spines of each tome, listening to the whisper of pages turning.

25.02.2025 18:59 — 👍 1    🔁 0    💬 1    📌 0
To prepare for this video, I asked ChatGPT to explain the physics behind how a star's velocity and mass are "estimated." What I found is that there are so many assumptions and fudge factors involved in calculating a star's mass that it starts to feel more like art than science. While I’m not saying MOND (Modified Newtonian Dynamics) is correct, I think the way we account for mass in galaxies is deeply flawed. When I pressed ChatGPT for deeper explanations, it provided formulae that rely on an ever-growing set of constants, many of which have imprecise values. For example, the relationship between a star's luminosity and its mass depends on an exponent (𝛼) that can range from 3 to 4 for different types of stars. That’s a huge range when you consider 2^3 = 8 versus 2^4 = 16. It feels like we’re supposed to just accept these "well-understood" constants without questioning their accuracy. In contrast, the velocity calculations using redshift seem much more straightforward. The physics behind redshift—Doppler shifts due to relative motion—is easier to understand and has fewer variables to fudge. So if we can’t properly account for the visible matter in galaxies, how can we confidently claim that “dark matter” exists at all? The existence of dark matter is inferred because the calculated mass of visible matter isn’t enough to explain galaxy rotation curves. But if the visible mass itself is based on shaky assumptions, that conclusion is on thin ice. Meanwhile, every experiment to directly detect dark matter has failed spectacularly—despite billions of dollars invested. These are incredibly expensive experiments, and after decades of "null" results, it’s worth questioning whether this money could be better spent elsewhere.

To prepare for this video, I asked ChatGPT to explain the physics behind how a star's velocity and mass are "estimated." What I found is that there are so many assumptions and fudge factors involved in calculating a star's mass that it starts to feel more like art than science. While I’m not saying MOND (Modified Newtonian Dynamics) is correct, I think the way we account for mass in galaxies is deeply flawed. When I pressed ChatGPT for deeper explanations, it provided formulae that rely on an ever-growing set of constants, many of which have imprecise values. For example, the relationship between a star's luminosity and its mass depends on an exponent (𝛼) that can range from 3 to 4 for different types of stars. That’s a huge range when you consider 2^3 = 8 versus 2^4 = 16. It feels like we’re supposed to just accept these "well-understood" constants without questioning their accuracy. In contrast, the velocity calculations using redshift seem much more straightforward. The physics behind redshift—Doppler shifts due to relative motion—is easier to understand and has fewer variables to fudge. So if we can’t properly account for the visible matter in galaxies, how can we confidently claim that “dark matter” exists at all? The existence of dark matter is inferred because the calculated mass of visible matter isn’t enough to explain galaxy rotation curves. But if the visible mass itself is based on shaky assumptions, that conclusion is on thin ice. Meanwhile, every experiment to directly detect dark matter has failed spectacularly—despite billions of dollars invested. These are incredibly expensive experiments, and after decades of "null" results, it’s worth questioning whether this money could be better spent elsewhere.

I asked chatgpt. I understand science now.

26.12.2024 02:16 — 👍 358    🔁 24    💬 32    📌 7

For those interested in the tectonics: this earthquake occurred near the Mendocino triple junction where 2 strike slip transform faults and a subduction zone meet: the Cascadia subduction zone to the north, the San Andreas fault to the south and the Mendocino transform fault to the west 🧪⚒️

05.12.2024 20:40 — 👍 208    🔁 63    💬 7    📌 7
DESY-Fellowships in Experimental Particle Physics - INSPIRE For our location in Hamburg we are seeking:DESY-Fellowships in Experimental Particle PhysicsRemuneration Group 13 | Limited: 2 years | Starting date: after a...

The DESY fellowship in Experimental Particle Physics call is open. This is a competitive named postdoctoral fellowship (deadline twice per year). Profile: People will be hired on ATLAS, CMS, Belle 2, Instrumentation, ALPS, and more!

Details in link😁

28.09.2024 10:27 — 👍 3    🔁 4    💬 1    📌 0
About 70,000 light-years across, NGC 247 is a spiral galaxy smaller than our Milky Way. Measured to be only 11 million light-years distant it is nearby though. Tilted nearly edge-on as seen from our perspective, it dominates this telescopic field of view toward the southern constellation Cetus. The pronounced void on one side of the galaxy's disk recalls for some its popular name, the Needle's Eye galaxy. Many background galaxies are visible in this sharp galaxy portrait, including the remarkable string of four galaxies just below and left of NGC 247 known as Burbidge's Chain. Burbidge's Chain galaxies are about 300 million light-years distant. NGC 247 itself is part of the Sculptor Group of galaxies along with shiny spiral NGC 253.

About 70,000 light-years across, NGC 247 is a spiral galaxy smaller than our Milky Way. Measured to be only 11 million light-years distant it is nearby though. Tilted nearly edge-on as seen from our perspective, it dominates this telescopic field of view toward the southern constellation Cetus. The pronounced void on one side of the galaxy's disk recalls for some its popular name, the Needle's Eye galaxy. Many background galaxies are visible in this sharp galaxy portrait, including the remarkable string of four galaxies just below and left of NGC 247 known as Burbidge's Chain. Burbidge's Chain galaxies are about 300 million light-years distant. NGC 247 itself is part of the Sculptor Group of galaxies along with shiny spiral NGC 253.

NGC 247 and Friends - ©Eric Benson

- Pic
- HD Pic
- About Astronomy Picture Of the Day

#astrophotos

Maintained by @shinyakato.dev

🔭 READ MORE 🔭

05.09.2024 08:00 — 👍 70    🔁 18    💬 1    📌 0
The RAS logo with text reading "Join us! Apply now"

The RAS logo with text reading "Join us! Apply now"

Job opportunity at the Royal Astronomical Society!

Do you have experience of academic publishing? Are you interested in joining the RAS Journals editorial team as Managing Editor as the #MNRAS approaches its bicentenary?

Apply by 20 September at: https://buff.ly/3X5vR6b

05.09.2024 08:18 — 👍 5    🔁 2    💬 0    📌 0
Preview
BBC World Service - More or Less, Tackling The Three-Body Problem Is the physics in Netflix's new show accurate?

Any 3 body problem fans out there?

Check out this BBC 'More or Less' podcast. It features my fab friend mathematical astrophysicist Dr Anna Lisa Varri, explaining the maths behind the sci-fi. Spoiler: she concludes the aliens aren't very good at maths. 🧪🔭⚛️👩‍🔬

📻: www.bbc.co.uk/programmes/w...

15.04.2024 07:22 — 👍 35    🔁 11    💬 5    📌 2

This is all I ask in life

15.04.2024 13:11 — 👍 888    🔁 64    💬 19    📌 0

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